Financial Instruments (Foreign Exchange Risk and Its Classification on Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Asset position
Asset position	$ 13.9	$ 17.9
Potential effect of rights to offset, asset position	(8.3)	(2.7)
Net derivative, asset position	5.6	15.2
Liability position
Liability position	30.8	14.2
Potential effect of rights to offset, liability position	(8.3)	(2.7)
Net derivative, liability position	22.5	11.5
Undesignated derivative instruments
Asset position
Asset position	13.9	17.9
Liability position
Liability position	15.2	6.5
Designated derivative Instruments
Asset position
Asset position	0.0	0.0
Liability position
Liability position	15.6	7.7
Foreign exchange contracts | Other current assets | Undesignated derivative instruments
Asset position
Asset position	13.9	17.9
Foreign exchange contracts | Other current liabilities | Undesignated derivative instruments
Liability position
Liability position	15.2	6.5
Interest rate contracts | Long term borrowings | Designated derivative Instruments
Asset position
Asset position	0.0	0.0
Liability position
Liability position	$ 15.6	$ 7.7